Table 1.
Baseline characteristics before and after PSM
| Characteristics | Before PSM | After PSM | ||||
|---|---|---|---|---|---|---|
| Very elderly (331) | Elderly (1753) | P value | Very elderly (331) | Elderly (331) | P value | |
| Age (year) | 83.4 ± 3.0 | 71.1 ± 4.1 | < 0.01** | 83.4 ± 3.0 | 71.8 ± 4.3 | < 0.01** |
| Sex | 0.104 | 0.436 | ||||
| Male | 183 (55.3%) | 1053 (60.1%) | 183 (55.3%) | 173 (52.3%) | ||
| Female | 148 (44.7%) | 700 (39.9%) | 148 (44.7%) | 158 (47.7%) | ||
| BMI (kg/m2) | 22.0 ± 3.4 | 22.5 ± 3.3 | 0.017* | 22.0 ± 3.4 | 21.8 ± 3.1 | 0.559 |
| T2DM | 67 (20.2%) | 289 (16.5%) | 0.096 | 67 (20.2%) | 62 (18.7%) | 0.624 |
| Smoking | 94 (28.4%) | 675 (38.5%) | < 0.01** | 96 (28.4%) | 95 (28.7%) | 0.864 |
| Drinking | 65 (19.6%) | 547 (31.2%) | < 0.01** | 65 (19.6%) | 74 (22.4%) | 0.390 |
| Hypertension | 158 (47.7%) | 591 (33.7%) | < 0.01** | 158 (47.7%) | 162 (48.9%) | 0.756 |
| CHD | 42 (12.7%) | 115 (6.7%) | < 0.01** | 42 (12.7%) | 34 (10.3%) | 0.329 |
| Surgical methods | 0.428 | 0.844 | ||||
| Open | 63 (19.0%) | 302 (17.2%) | 63 (19.0%) | 65 (19.6%) | ||
| Laparoscopic | 268 (81.0%) | 1451 (82.8%) | 268 (81.0%) | 266 (80.4%) | ||
| Tumor location | 0.001** | 0.383 | ||||
| Colon | 192 (58.0%) | 838 (47.8%) | 192 (58.0%) | 203 (61.3%) | ||
| Rectum | 139 (42.0%) | 915 (52.2%) | 139 (42.0%) | 128 (38.7%) | ||
| Tumor stage | 0.035* | 0.288 | ||||
| I | 53 (16.0%) | 321 (18.3%) | 53 (16.0%) | 49 (14.8%) | ||
| II | 134 (40.5%) | 801 (45.7%) | 134 (40.5%) | 154 (46.5%) | ||
| III | 144 (43.5%) | 631 (36.0%) | 144 (43.5%) | 128 (38.7%) | ||
T2DM, type 2 diabetes mellitus; BMI, body mass index; PSM, propensity score matching; CHD, coronary heart disease
Variables are expressed as the mean ± SD, n (%), *P-value < 0.05, ** P-value < 0.01